Machines used to perform hemodialysis are of different varieties. The following fuctions are carried out by these machine
Proportionate mixing of dialysate concentrate and treated water to form dialysate. The composition of dialysate is similar to blood without cells, proteins, lipids and some other complex salts. The dialysate consists mainly of water and various main salts and ions eg sodium, potassium, chloride , bicarbonate, calcium etc.
The dialysate is freed of dissolved gases, and is heated to body temperature. Very low temperature may cause hypothremia and high temperature of dialysated may cause fever.
These machines has a self cleaning mechanism with hot water and various chemicals to take care of various pathogens.
It pulls blood at speeds set by the dialysis personnel and also supplies dialysate at required rate. It can also create negative pressure so that extra fluid can be removed from the body.
During dialysis a person may require various medicines to be administered. This is facilitated by the machine.
Additionally, machines have safety measures. It can detect air in blood so that air does not enter patients’ blood vessels. The machines go into auto shut mode if air is detected in returning blood.
If blood gets hemolysed (hemoglobin leaks out of RBCs) a serious situation for a patient may develop. Machines can detect leaked hemoglobin and sound an alarm.
Most newer machines have built in blood pressure monitoring system. If blood pressure becomes lower or higher than set range, an alarm is sounded and corrective measures can be taken.
Machines also monitor the flow of blood from the patient. If the pressure in the tubing is recorded higher or lower than set limits, alarms sound for the call to dialysis nurse or technician.
Modern machines can also measure dialysis dose. (more about this later in dialysis adequacy)
Next topic in dialysis series is dialysers.